By Brad Rippey, USDA Meteorologist, Office of the Chief Economist, World Agricultural Outlook Board, Washington, D.C.
During the five-week period ending Jan. 5, 2016, contiguous U.S. drought coverage fell to 18.39 percent—a decrease of 2.19 percentage points. This also represents the smallest areal coverage of U.S. drought in more than five years, since Dec. 7, 2010. Perhaps not coincidentally, the U.S. drought minimum of 2010 occurred near the end of the most recently completed El Niño, which lasted from the summer of 2009 to the spring of 2010.
Since mid-October 2015, a procession of storms, in part driven by a near-record-strength El Niño, has significantly reduced U.S. drought coverage from 34.78 to 18.39 percent—a drop of 16.39 percentage points.
For many areas of the country, drought has become an afterthought in the face of heavy precipitation, record flooding, winter tornado outbreaks, and more. December featured heavy, drought-easing or -eradicating precipitation in the Northwest, torrential precipitation from northeastern Texas into the middle Mississippi Valley, and additional heavy rain in parts of the Southeast. As the New Year began, a marked southward shift in the jet stream allowed colder air to invade the central and eastern U.S., but more importantly, brought the season’s most significant precipitation to central and southern California. Such a southward shift in the primary storm track is a hallmark of El Niño, especially in the January-March time frame, and could lead to significant, mid- to late-winter precipitation from southern California to the southern half of the Plains, as well as areas along and near the Gulf Coast and the southern Atlantic Coast.
According to the California Department of Water Resources, the average water content of the high-elevation Sierra Nevada snowpack climbed to 12 inches by Jan. 6, slightly above average for this time of year. By April 1, the traditional peak snowpack date, the Sierra Nevada snow should contain nearly 30 inches of liquid. With more than half of California’s winter wet season still ahead and a strong El Niño in place, forecasters are optimistic that California’s drought situation will begin to improve. However, experts caution that effects of California’s four-year drought could persist, in part due to long-term factors such as tree mortality—which could lead to future wildfires—and losses of groundwater—which is not always easily replaced. In addition, California’s intrastate reservoirs held just 52 percent of their normal water volume on Nov. 30, and that number may not appreciably improve until high-elevation snow begins to melt in the spring.
On Jan. 5, nearly half (45 percent) of the western U.S. remained in drought, down from 49 percent in early December. Nearly all (97 percent) of California was in drought on Jan. 5, unchanged from five weeks ago. Farther north, however, drought coverage during the same five-week period decreased from 96 to 77 percent in Oregon and from 64 to 25 percent in Washington
On Jan. 5, drought was affecting just 12 percent of the U.S. cattle inventory, down from an autumn 2015 peak of 27 percent.
On Jan. 5, the portion of the U.S. winter wheat production area in drought stood at 12 percent, down from an autumn peak of 29 percent on Oct. 20.
Weather outlook: For the remainder of the week, a mild, active weather pattern will return to the eastern half of the U.S. East of the Rockies, accumulating snow should be confined to an area stretching from the central High Plains into the Great Lakes region, although weekend snow could become heavy in the latter region. Meanwhile, storm-total rainfall should reach an inch or more in parts of the South, East, and lower Midwest. Precipitation will be slow to exit the Northeast, lingering through the weekend. Elsewhere, heavy snow will shift from the Southwest to the central Rockies before ending, although snow showers will return to the Far West—including the Sierra Nevada—during the weekend.
PLEASE NOTE: The next issuance of this emailed drought update will be Thursday, Feb. 4, 2016, unless conditions warrant an earlier release.
The “U.S. Crops in Drought” products will be produced weekly and are online:
http://www.usda.gov/oce/weather/Drought/AgInDrought.pdf
Archived “U.S. Crops in Drought” files can be downloaded:
http://drought.unl.edu/Planning/Impacts/USAginDroughtArchive.aspx